Vehicle data bus system with positioning means

ABSTRACT

A vehicle data bus system includes locating means which comprise a locating computing unit and a locating sensor system which contains at least one GPS receiver with associated GPS antenna and gyro data acquisition means, and a data bus via which connects a plurality of bus users in data communication with one another. The locating means contain a locating module which is embodied as one of the bus users and is configured to receive at least wheel speed data and forward/backward direction of travel data via the data bus, to acquire at least vehicle position data, direction of travel angle data, travel speed data and altitude position data as well as to output this acquired data onto the data bus. For this purpose, the locating module contains the location computing unit, the GPS receiver and a gyroscope or means for the bus-end reception and evaluation of gyro data of a travel dynamics/traction control system.

This application claims the priority of PCT International ApplicationNo. PCT/EP00/08735, filed 07 Sep. 2000 and German patent document 199 44177.4, 15 Sep. 1999, the disclosure of which is expressly incorporatedby reference herein.

BACKGROUND AND SUMMARY OF THE INVENTION

The invention relates to a vehicle data bus system having a locationdetermining arrangement that includes a locating computing unit and alocating sensor system having at least one GPS (Global PositioningSystem) receiver with associated GPS antenna and gyro data acquisitionmeans, the data bus system also having a plurality of bus usersconnected to a data bus, for data transmission to one another.

European patent document EP 789 343 A1 discloses a vehicle data bussystem of the generic type, having locating means and a plurality ofconnected bus users. GPS receivers, gyro data sensors, wheel speedsensors, tachometers, odometers and acceleration sensors can be used aslocating sensor systems. A locating computing unit uses the data of thelocating sensor system to determine the position data which can beoutput onto the data bus.

Motor vehicles of advanced design frequently include positiondetermining devices that operate on the basis of the GPS, and whennecessary, the latter are supported by further position-determiningdevices for compound navigation (for example, a gyroscope and anodometer). In addition, a plurality of vehicle-mounted components,(conventionally control devices referred to herein as “bus users”, forperforming local vehicle-mounted control functions), are frequentlyconnected to one another via a data bus which can be part of an entiredata bus network.

Recently, telematics service units are also becoming significant bususers. Such telematics service units have a communications connection,on the one hand, to the “vehicle world” via the vehicle data bus and, onthe other hand, to remote stations, which are external to the vehicle,via one or more wireless transmission channels. They may be used forexample, to perform functions such as emergency calls, pursuit ofthieves, determination of traffic situation data of sample vehicles etc.

In earlier motor vehicles of this type, the locating devices on the onehand and the data bus with connected vehicle control devices on theother hand formed separate vehicle subsystems, and frequently only oneof the two was implemented. The locating devices themselves werefrequently composed of a relatively large number of individualcomponents. U.S. Pat. No. 5,644,317 for example, discloses an automaticvehicle locating system having a locating sensor system composed of aplurality of individual sensor units, and a locating computing unitwhich receives output signals of the various locating sensor units. Thelocating computing unit outputs data relating to the vehicle positionand vehicle situation to an external unit via a wireless communicationschannel for presentation of the transmitted position/situation data.

A vehicle-position-determining system disclosed in U.S. Pat. No.5,740,049 determines a first temporary position information item byreference to the output signals of a vehicle speed sensor and agyroscope, and corrects it by deriving a second temporary positioninformation item by reconciliation with stored route data. A thirdtemporary position information item is acquired from the output signalof a GPS receiver. By evaluating or reconciling the various temporaryposition information items, a definitive vehicle position is determinedand displayed on a screen in a road map view.

The locating devices are often an integrated component connectedupstream of a vehicle navigation unit, for the sole purpose of supplyingposition and situation data (i.e., orientation of the vehicle in space)data for navigation and/or for visually displaying determined positionor situation of the vehicle. See, for example, European patent documentEP 0 675 341 A1 and International patent document WO 98/36288 A1.

International patent document WO 98/10246 A1 discloses a device forrecording geographic data which, depending on the configuration, can bedetermined as a portable device or for installation in a vehicle, forexample, and has not only position-determining means but also videocameras for recording images. A computer unit receives the data outputby the positioning-determining means and the video cameras and evaluatesit to determine the direction of the image relative to the device, orthe geographic data for an object sensed with the camera. The device canhave a communications connection via a wireless communications channelto a remote station, for example a central processor unit there.

German patent document DE 196 40 735 A1 discloses a telematics devicefor a motor vehicle, which includes a car radio with an RDS module and abuilt-in locating system with GPS module, a radio telephone with GSMmodule, a memory and a display. The RDS module, the GPS module and theGSM module are installed together with a voice unit and the car radio ina housing of the telematics device. The housing has antenna terminalsfor at least the car radio, the GSM module and the GPS module as well asinterfaces for at least one CAN bus and/or one further data bus as wellas for at least one loudspeaker and/or a microphone. By means of travelsensors (for example wheel sensors, a direction sensor and/or the GPSmodules the position of the vehicle can also be connected and output ona digital map of the visual display. By communicating with a controlcenter or a navigation system which is built into the telematics deviceor a navigation module which can be connected thereto via the CAN bus orthe further data bus, it is possible to calculate a desired travel routewhich is then displayed on the visual display. Via the CAN bus and/orthe further data bus, the telematics device can influence an enginecontrol unit which forms a further bus user.

One object of the invention is to provide a vehicle data bus system ofthe type described above which is flexible and convenient to use, andcan be satisfactorily standardized.

This and other objects and advantages are achieved by the vehicle databus system according to the invention, in which a locating module isembodied in a specific way as one of the bus users connected to the databus. Components of the locating module which are used for locating thevehicle are integrated primarily into a single structural unit. Theassociated locating sensor system is at least partially integrated intothe locating module and also connected to the data bus so that thelocating module acquires at least part of the necessary locating sensordata internally, and also receives it via the data bus. Specifically,the locating module contains a locating computing unit, which performsthe computational determination of a position, and a GPS receiver. Inaddition, it has a gyroscope or means for receiving corresponding gyrodata via the data bus from a travel dynamics/traction control system ifthe latter comprises the respective gyro data acquisition sensor system(as, for example, in some conventional travel dynamics control systems).

As a result of the modular combination and the data bus connection ofthe locating apparatus, they can be standardized for use in differentvehicles (and in different countries) without extensive adaptationmeasures, and can provide appropriate locating information on the databus in a flexible way according to need, from which data bus users. Thelocating information which is thus made available comprises, inparticular, vehicle position data, direction of travel angle data,travel speed data and altitude data (data on the instantaneous altitudeposition of the vehicle above sea level) (NN). In a preferred embodimentof the invention, a locating precision classification (location quality)is also provided in the form of an identifier which indicates the degreeof unreliability of the calculated position data.

In order to determine the locating information, the locating module usesnot only the gyro data and the GPS data, but also wheel speed data anddata indicating whether the vehicle is driving forward or backward at agiven time, which it obtains from the data bus. The locating informationcan be used, in particular for vehicle control units which performvarious vehicle-related functions, such as travel dynamics control,anti-lock brake control, traction control, engine control and gearboxcontrol, by display instruments such as a combination instrument or by aspecific comfort information display, and also by communication unitswhich communicate with vehicle-mounted components via the data bus andwith remote components, external to the vehicle, via a wirelesscommunications channel.

In another embodiment of the vehicle data bus system according to theinvention, the structural unit which represents the locating module alsocontains an integrated GPS antenna so that it is unnecessary to mount aseparate GPS antenna on the vehicle or to connect it to the locatingmodule.

In still another embodiment of the invention, a navigation unit, whichreceives the position data from the locating module, is provided as afurther bus user. By means of a conventional map-matching process inwhich this position data is compared with stored travel network data, itacquires improved position information with a new location positionclassification (location quality). The navigation unitcharacteristically feeds back the corresponding position correction datavia the data bus to the locating module which can use said data forprecision-improving correction reconciliation.

In yet another embodiment of the invention, one or more telematicsservice units are provided as further bus users, which use the locatingdata acquired from the locating module (for example for an emergencycall function) to pursue thieves and/or to determine traffic situationsusing sample vehicles (what is referred to as a floating car datamethod).

According to another embodiment of the invention, an engine and/or agearbox control unit, provided as a further bus user, utilizes the databus connection, inter alia, to read in the altitude position data madeavailable by the locating module. As a result, it is possible todispense with an altitude sensor which is conventionally present inmodern units of this type.

Finally, according to another feature of the invention, the locatingmodule is part of a further bus user, which uses the locating computingunit for additional tasks.

Other objects, advantages and novel features of the present inventionwill become apparent from the following detailed description of theinvention when considered in conjunction with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a partial schematic representation of a vehicle data bussystem with locating module with integrated gyroscope and external GPSantenna according to the invention;

FIG. 2 shows a data bus system corresponding to FIG. 1, with anadditional navigation unit;

FIG. 3 shows a data bus system corresponding to that of FIG. 2, with alocating module which does not have a gyroscope and which receives gyrodata from the bus; and

FIG. 4 shows a data bus system corresponding to FIG. 2, with GPS antennaintegrated into the locating module.

DETAILED DESCRIPTION OF THE DRAWINGS

The vehicle data bus system which is illustrated in FIG. 1 (showing onlythose components which are of specific interest here) contains a databus 1 to which a plurality of bus users are connected. Only a locatingmodule 2 and a telematics service block 3 are shown explicitly, with oneor more telematics service units for corresponding functionalities (forexample emergency calls, pursuit of thieves and the determination oftraffic situations using sample vehicles) being combined by thetelematic service block 3, for simplicity. The locating module 2 isprovided as a component that can be built on in a uniform fashion; itcontains a locating computing unit 2 a, a GPS receiver 2 b and agyroscope 2 c in an integrated form in this example.

An external GPS antenna 4 which is mounted at a suitable location on thevehicle is connected to the GPS receiver 2 b. The locating module 2 iscoupled into the data bus 1 via a corresponding bus interface, fromwhich it reads in wheel speed data and forward/backward direction oftravel data. The wheel speed data can be supplied, for example, in theform of rotational speed sensor pulses per time unit by a traveldynamics/traction control system which also acquires this data for itsown use, in a known manner. The travel dynamics/traction control systemcan be, for example, an anti-lock brake system (ABS) or a traveldynamics control system which is used by the applicant under theabbreviation ESP (electronic stability program). The forward/backwarddirection of travel data indicates whether the vehicle is travellingforward or backward at a given time, and can originate, for example,from reverse-gear detection means, which determine whether or not thereverse gear is engaged.

Data that are necessary for locating, which the locating module 2 doesnot acquire from the data bus 1, are supplied by the integrated locatingsensor units, specifically GPS data of the GPS receiver 2 b and gyrodata of the gyroscope 2 c. The locating computing unit 2 a then carriesout the actual computational locating process. (The term “locating” isused here in a broad sense, which includes both a determination of theposition of the vehicle and its altitude, and orientation in space.)That is, the locating computing unit 2 a determines vehicle positiondata with its locating precision classification (location quality),direction of travel angle data, travel speed data and altitude data(altitude of the vehicle above sea level (NN)) at a given time. Thelocating computing unit 2 a also contains time-determining means whichprovide highly precise time information corresponding to a radio clock,the time valid in respective countries being given throughout the world,for example according to the GMT or UTC standard, without the userhaving to perform complicated menu settings for this purpose. Thedirection of travel angle data contains not only actual angleinformation but also offset, drift and scaling factor information.

The locating computing unit 2 a feeds determined, conditioned locatingdata onto the data bus 1 where it is made available to the other bususers, for example to the telematics service units 3 and/or vehiclecontrol units (not shown), for example engine and/or gearbox controlunit, which are connected to the data bus 1. A connected engine orgearbox control unit can accept, in particular, the altitude positioninformation made available by the locating module 2 on the data bus 1and in this way does not require its own altitude sensor. When thesystem is started, the altitude value when the vehicle was last switchedoff is expediently used until current altitude position data isavailable again.

As is apparent from the explanations above, the locating module 2performs a locating process using a plurality of parallel inputinformation items, specifically the internally acquired GPS data, theinternally acquired gyro data and the wheel speed data received via thedata bus 1, which is also used by the locating module 2 to perform anodometer function.

The vehicle data bus system illustrated in FIG. 2 (again, with onlythose components which are specifically of interest here) correspondsessentially to that in FIG. 1. (Corresponding reference symbols are usedfor functionally identical elements.) The system in FIG. 2, however,contains a navigation unit 5 as a further bus user. The navigation unit5 receives the various locating data items supplied by the locatingmodule 2 via the data bus 1, and uses the received position data in aconventional map-matching process in which the vehicle positiondetermined by the locating module 2 is reconciled with data in adigitally stored travel network map. In this manner, the navigation unit5 determines a precision classification (locating quality) and outputsthis and accompanying travel network information (such as names oflocalities and roads), onto the data bus 1. The bus users connected tothe data bus 1 can then use for this purpose the precise vehicleposition data made available by the navigation unit 5 if they requirevehicle position data. This applies in particular also the telematicsservice units 3.

The navigation unit 5 also outputs onto the data bus 1 positioncorrection data which represents the possible deviation of the precisevehicle position determined by it from the vehicle position determinedby the locating module 2. The locating module 2 can obtain this fed-backposition correction data or these correction parameters from the databus 1 and use them for corresponding correction of the location which itdetermines, in order to improve the precision of theposition-determining process.

The vehicle data bus system in FIG. 3 corresponds to that in FIG. 2,with a modified locating module 2′ containing only the locatingcomputing unit 2 a and the GPS receiver 2 b, but no gyroscope. In thiscase, the locating module 2′ contains means for the bus-end receptionand evaluation of gyro data of a travel dynamics/traction controlsystem, e.g. by an ESP controller. This leads to satisfactory results ifthe gyro sensor means of the travel dynamics/traction control systemhave an adequate level of precision or efficiency and reliability. Thetravel dynamics/traction control system makes available the determinedgyro data on the data bus 1, from where it can be called by the locatingmodule 2′.

The vehicle data bus system illustrated in FIG. 4 corresponds to that inFIG. 2, with a modified locating module 2″, that also contains anintegrated GPS antenna 4 a. As a result, the need for a GPS antennawhich is to be separately mounted on the vehicle and connected to thelocating module is dispensed with.

As the above exemplary embodiments make clear, the present inventionimplements a vehicle data bus system in which a locating module which isimplemented as a stand-alone structural unit (for example in the form ofa separate box or plug-in module) is integrated into the bus system as abus user and contains all the components which are used for determininglocations and receives input information necessary for this purpose viathe data bus. The locating module can be used as a small standard boxthroughout the world in a wide variety of vehicles without extensiveadaptation measures. Even without an implemented navigationfunctionality or emergency call functionality, it is possible to use thelocation-related services, such as pursuit of thieves, the determinationof traffic situations using sample vehicles etc. by means of thelocating data supplied by the locating module.

The use of the locating data provided by the locating module makes thesystem independent of the manufacturers of communications devices whichare used, such as telephone sets. The locating data of the locatingmodule can be used to display the compass direction and/or degrees oflongitude and of latitude of the current vehicle position, which can behelpful for breakdown information, for example. Furthermore, ahigh-precision clock with the display of the current time in any countrythroughout the world can be implemented without complicated menusettings by the user. The time can be displayed, for example, in acombination instrument or in an auxiliary heating module, so that theneed for a separate clock chip can be avoided.

The use of altitude information of the locating module by an engineand/or gearbox electronic system makes it possible to avoid the need fora separate altitude sensor. The locating information which is madeavailable by the locating module in a standardized form and whichrelates to the position, locating precision classification (locatingquality), direction of travel angle, direction of rotation, altitudeposition, inclination of the vehicle, etc. can be used by means of thedata bus in a flexible way by the various systems which are based onlocating information, for, for example, emergency calls, calling taxis,navigation, devices which warn of imminent bends, the determination oftraffic situations using sample vehicles, travel dynamics controlsystems, anti-lock brake systems, traction controllers, gearboxes,engine electronic systems, combination instruments and supplementaryinformation.

The foregoing disclosure has been set forth merely to illustrate theinvention and is not intended to be limiting. Since modifications of thedisclosed embodiments incorporating the spirit and substance of theinvention may occur to persons skilled in the art, the invention shouldbe construed to include everything within the scope of the appendedclaims and equivalents thereof.

What is claimed is:
 1. A vehicle data bus system comprising: a data buswhich connects a plurality of bus users in data communication with oneanother; and locating apparatus, including a locating module connectedas one of the bus users, said locating module being configured todetermine vehicle position data, direction of travel angle data, andtravel speed data and to output this determined data onto the data bus;wherein, the locating module has a locating computing unit and alocating sensor system which comprises at least a GPS receiver withassociated GPS antenna, and a gyro data-determining means; the locatingmodule is configured to receive wheel speed data and forward/backwarddirection of travel data via the data bus; the locating module isfurther configured to determine position data and to output saidaltitude position data onto the data bus; and the gyro data-determiningmeans comprises one of gyro data-sensing means in the form of agyroscope, and means for the bus-end reception and evaluation of gyrodata of a travel dynamics/traction control system.
 2. The vehicle databus system according to claim 1, further comprising means for providinglocation precision classification information which indicates a degreeof unreliability of calculated position data.
 3. The vehicle data bussystem according to claim 2, wherein the locating precisionclassification is output onto the data bus.
 4. The vehicle data bussystem according to claim 1, wherein the locating module contains anintegrated GPS antenna.
 5. The vehicle data bus system according toclaim 1, further comprising an additional bus user in the form of anavigation unit, which receives vehicle position data from the locatingmodule via the data bus, and by means of a map-matching processdetermines position correction data, which it inputs into the data busin order to feed it back to the locating module.
 6. The vehicle data bussystem according to claim 5, wherein the navigation unit determines acorrected, precise vehicle position with a new locating precisionclassification and outputs it onto the data bus.
 7. The vehicle data bussystem according to claim 5, wherein the navigation unit determinesaccompanying travel network information and outputs it onto the databus.
 8. The vehicle data bus system according to claim 1, wherein: thelocating module is part of a further bus user; and the locatingcomputing unit is used by the further bus user, for additional tasks. 9.A vehicle data bus system comprising: a data bus which connects aplurality of bus users in data communication with one another; andlocating apparatus, including a locating module connected as one of thebus users, said locating module being configured to determine vehicleposition data, direction of travel angle data and travel speed data, andto output this determined data onto the data bus; wherein, the locatingmodule has a locating computing unit and a locating sensor system whichcomprises at least a GPS receiver with associated GPS antenna and gyrodata-determining means; the locating module is configured to receivewheel speed data and forward/backward direction of travel data via thedata bus; the locating module is further configured to determinealtitude position data and to output acquired altitude position dataonto the data bus; and the gyro data-determining means comprises one ofgyro data-sensing means in the form of a gyroscope, and means for thebus-end reception and evaluation of gyro data of a traveldynamics/traction control system; and the bus system includes at leastone telematics service unit coupled thereto as a bus user, which usesdata acquired from the locating module or from a navigation unit.
 10. Avehicle data bus system comprising: a data bus which connects aplurality of bus users in data communication with one another; andlocating apparatus, including a locating module connected as one of thebus users, said locating module being configured to determine vehicleposition data, direction of travel angle data and travel speed data, andto output this determined data onto the data bus; wherein, the locatingmodule has a locating computing unit and a locating sensor system whichcomprises at least a GPS receiver with associated GPS antenna and gyrodata-determining means; the locating module is configured to receivewheel speed data and forward/backward direction of travel data via thedata bus; the locating module is further configured to determinealtitude position data and to output acquired altitude position dataonto the data bus; and the gyro data-determining means comprises one ofgyro data-sensing means in the form of a gyroscope, and means for thebus-end reception and evaluation of gyro data of a traveldynamics/traction control system; and said altitude position data fromthe locating module is supplied via said data bus to an engine or gearbox control as a further bus user, which uses said altitude positiondata in place of data from a separate altitude sensor.